This specification relates to data processing and cross-device online activity.
Users can be exposed to a particular portion of content, an online advertisement, a website, audible information, or a video channel through the use of numerous various devices, including desktop computers, smartphones, tablets, gaming systems, and other devices (e.g., virtual assistant devices). Because users can be exposed to content on multiple different devices, it is difficult to determine whether a particular user of a particular device has previously been exposed to a particular portion of content while previously using a different device. Therefore, a particular user may be exposed to the same content on various different devices.